motor output voltage?

[christ371]

I am trying to learn about the relationship between the input voltages of a driver board. How does it relate to the motor output voltage? Let’s say I have a driver board it out puts 1.5 amps and the input voltage is 24 volts. Are the pulses that charge the windings 1.5 amps at 24 volt?

[wildwestpat]

The motor has two voltages of interest - firstly the steady state voltage applied to the winding for the rated current and - secondly the insulation breakdown voltage at the highest temperature the motor can reach.

The electronics switch the appled power on and off to regulate the current. The current increases slowly due to the inductance of the motor coil. Thus there is no direct relationship between the voltage of the driving electronics and the rated motor other than the need to stay within the safe working limits of the componets used. The electronics use various methods to determine the point at which the drive pulse needs to stop to stay with in the safe current rating of the motor winding.

There is no harm, apart from loss of power, in setting the current lower than the maximum for the motor.

On the assumption that this is a stepper driver a higher voltage gives better high speed potential.

Regards

Pat

[Crevice Reamer]

Hi Chris.

Some of this basic CNC info may be helpful to you:

http://crevicereamer.com/Page_2.html

CR.

[christ371]

Thanks for your help. I have decided to use a keling 4020 driver with a vexta pk226-02a a “6 wire 2A unipolar motor”. The 4020 allows me to change the amp output. I’m running the motors at low rpm no more than 50 rpm. So I will wire the motor as bipolar. The motor specifies 1.4A with bipolar wiring, The driver adjustment jumps from 1.25 amps to 1.5. If I run these motors .1amp over the suggested current will that damage my motors? There is some difference in the tork from my machine when I change between these settings.

[Crevice Reamer]

With a six wire motor, you only have the choice of Unipolar, Bipolar Series or Half-coil. If all you need is 50 RPM, I assume you are wiring them Bipolar Series. Now if you wanted more speed, then Half-coil would be the way to wire them.

You CAN run the motor slightly over-Amped, but this may cause overheating so watch it carefully. You want the motors to run about 160 Fahrenheit or less. You COULD go up to as much as 180, but that's pushing it.

CR.